Theft alarm devices are generally categorized as being either permanently attached to an object, installed in a location, or transportable, for use in more than one location or on more than one object. Non-portable theft alarm devices generally require an installation, use an outside power source, and are complex and relatively expensive. Portable theft alarm devices have been developed for many limited and some general applications. Magnetic, electronic and motion detection systems are several methods employed to detect the theft of an object. U.S. Pat. No. 4,584,571 is an example of a limited use theft alarm device utilizing a magnet attached to an object and sensors to detect the separation of the protected object from an area in close proximity to the sensors. Another limited use device, installed on an object such as a doorknob, is U.S Pat. No. 3465325, which detects a change in electrical capacity when touched. An example of a limited use theft alarm requiring an installation can be found in U.S. Pat. No. 4,841,285, which uses a mercury type motion detection device for protection of a display case. U.S. Pat. No. 3,988,724, is a portable motion detection device which uses a two part transmitter and receiver which detects separation of the two parts. U.S. Pat. No. 5,317,304 uses a motion detection system coupled with a computer to discern different types of movement. U.S. Pat. No. 3,710,371, a portable device, utilizes a mercury type motion detection device, but is not designed to be used on objects of an irregular, angular or curved surface and is somewhat large to be conveniently carried on one's person. All of the portable alarms heretofore known suffer from a number of disadvantages:
(a) Their size makes them difficult to transport easily on one's person. PA1 (b) Many require the use of more than one device for the system to function. PA1 (c) Most are designed for use on only one object. PA1 (d) Most cannot be used on objects composed of any type of material, or installed on objects with an irregular, angular or curved type of surface. PA1 (e) An outside power source is required for many portable alarms. PA1 (f) The complexity of the alarm circuitry and the construction of the entire alarm apparatus causes the final cost to be expensive. PA1 (g) Many are designed to be inconspicuous or to produce a silent type of alarm thereby offering no method to deter a potential thief. PA1 (a) to provide a single unit portable theft alarm device that is of minimum dimensions and weight that can be easily carried on one's person. PA1 (b) to provide methods of either permanent attachment or easily removeable attachment of the alarm device to objects to be secured. PA1 (c) to provide an alarm device that offers a visual deterrent to a potential thief PA1 (d) to provide an alarm device that can be mounted to objects of any type of material and shape. PA1 (e) to provide an alarm device that is simple to use and easily activated and deactivated only by the owner.
Often one of the devices must be installed on the object being protected, which may require tools and a time consuming installation. Where a transmitter is used, a signal is sent to a second device, a receiver, which then generates an alarm signal.